#pragma once
#include <etcd/Client.hpp>
#include <etcd/KeepAlive.hpp>
#include <etcd/Response.hpp>
#include <etcd/Watcher.hpp>
#include <etcd/Value.hpp>
#include <thread>
#include "../common/logger.hpp"
namespace chen_im
{

//服务注册客户端类
class Registry
{
public:
    using ptr = std::shared_ptr<Registry>;
    Registry(const std::string& host)
        :_client(std::make_shared<etcd::Client>(host))
        ,_keep_alive(_client->leasekeepalive(3).get())
        ,_lease_id(_keep_alive->Lease())
    {}

    ~Registry()
    {
        _keep_alive->Cancel(); 
    }
    
    bool registry(const std::string& key, const std::string& val)
    {
        auto resp = _client->put(key, val, _lease_id).get();
        if(resp.is_ok() == false)
        {
            LOG_ERROR("注册数据失败：{}", resp.error_message());
            return false;
        }

        return true;
    }

    
private:
    std::shared_ptr<etcd::Client> _client;  //客户端
    std::shared_ptr<etcd::KeepAlive> _keep_alive; //保活对象
    uint64_t _lease_id; //租约id
};

//服务发现客户端类
class Discovery
{
public:
    using ptr = std::shared_ptr<Discovery>;
    using NotifyCallback = std::function<void(std::string, std::string)>;
    Discovery(const std::string& host, const std::string& basedir,
            const NotifyCallback& put_cb, const NotifyCallback& del_cb)
            :_client(std::make_shared<etcd::Client>(host)),
             _put_cb(put_cb), _del_cb(del_cb)
    {
        auto resp = _client->ls(basedir).get();
        if(resp.is_ok() == false)
        {
            LOG_ERROR("获取服务信息数据失败：{}", resp.error_message());
        }

         int sz = resp.keys().size();
            for (int i = 0; i < sz; ++i) {
                if (_put_cb) _put_cb(resp.key(i), resp.value(i).as_string());
            }

        //然后进行事件监控，监控数据发生的改变并调用回调进行处理
        _watcher = std::make_shared<etcd::Watcher>(*_client.get(), basedir,
            std::bind(&Discovery::callback, this, std::placeholders::_1), true);
    }

private:
    void callback(const etcd::Response &resp) {
        if (resp.is_ok() == false) {
            LOG_ERROR("收到一个错误的事件通知: {}", resp.error_message());
            return;
        }
        for (auto const& ev : resp.events()) {
            if (ev.event_type() == etcd::Event::EventType::PUT) {
                if (_put_cb) _put_cb(ev.kv().key(), ev.kv().as_string());
                LOG_DEBUG("新增服务：{}-{}", ev.kv().key(), ev.kv().as_string());
            }else if (ev.event_type() == etcd::Event::EventType::DELETE_) {
                if (_del_cb) _del_cb(ev.prev_kv().key(), ev.prev_kv().as_string());
                LOG_DEBUG("下线服务：{}-{}", ev.prev_kv().key(), ev.prev_kv().as_string());
            }
        }
    }  

private:
    NotifyCallback _put_cb;
    NotifyCallback _del_cb;
    std::shared_ptr<etcd::Client> _client;
    std::shared_ptr<etcd::Watcher> _watcher;
};

}